MAF and Wideband O2 Sensor Testing for a P0172 [Rich Condition]

The car being tested is a 2007 Suzuki SX4 but the methods shown apply to all cars! It is very difficult sometimes to identify proper operation of a wideband O2 sensor and also the calibration of the MAF sensor. In this video we cover both of these tests very thoroughly and are able to fix the car.

00:00 - customer complaint, repair history (rich condition P0172)
02:13 - upstream and downstream oxygen sensor testing
09:00 - fuel trim analysis
09:55 - common causes of rich conditions
10:15 - MAF sensor testing begins
16:30 - MAF sensor inspection and cleaning
20:00 - adding fuel to confirm wideband function
25:40 - lab scope tests of the MAF sensor
30:10 - day 2, used MAF sensor comparison
37:10 - counter fuel trim numbers (is it fixed?)
42:06 - scan data MAF and Calculated Load numbers after repair
46:55 - lab scope tests on the used MAF

ScannerDanner Tools:

On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!

Disclaimer:
Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC.

[ScannerDanner]

Don't forget to check the description for time stamps and links to the other videos mentioned. Thank you everyone and Merry Christmas!

[justinballard]

4:57 you can rapidly stab the brake pedal to force a lean condition also. Eric o from sma taught me that trick

[coycarlson]

Love living in the day and times of our internet technology especially being able to watch you teach me how to PROPERLY troubleshoot and repair vehicles - if I learn half of what you KNOW and Teach - I will be a good tech 🙂 - That being said, you are inspiring and I want to be just as good as you - not just half as good 😏 . The reality of it is though - I DO recognize that the knowledge you possess and teach Is many years of experience 👍 SO being 60 years old myself - and a DIY mechanic ( generally) I GREATLY APPRECIATE YOU and your YouTube video’s ✌️

[JimmyMakingitwork]

This is one of the things we always have to weight in the shop. How many hours, or how much further testing should we do, vs a fairly inexpensive part to test. Always a balance and what matters most is understanding the systems and when to do this type of diagnosis.
Great work as always.

[mike-ypuk]

I love the pre-inspection. I pull a code and look under the hood. This is the perfect time to fix oblivious damage. I get cars with partially installed air tubes or bad rodent damage and diag time goes down drastically. This technique is good for seeing the types of systems the car is using. ECT... Sometimes they will have a repair free by the dealer tsb or bulletin. You get burned and then you start to look first before you cross that street. Lol I love what this channel has to offer a technician who wants to better themselves.

[simonparkinson]

48:10 Absolutely!
Once I have determined sensor ground is intact, I always use sensor grounds as reference when scoping.
I love the independent channel grounds of the Pico 4425 for this reason and cringe when I see people lumping all those grounds together on battery negative.
Maybe they do it because Bernie said it so many times? But with a common ground scope, that's all you can do.
While peak detect on snap-on can be useful in ensuring fast signals are not missed on a long timebase, it can lead you into seeing problems that aren't there - you're probably seeing the radiated signals from secondary ignition under load, which will be filtered out by the ECM.

[GeminiSeven]

Thanks so much Paul and Danner for another great video. Lots of good tips and it is great when we get to see you go through cases like this that might not make sense at first but through knowledge of basics you show us how to interpret the data and come to a solid conclusion and fix. Merry Christmas to you
and your families and I wish you a wonderful holiday. Thanks so much.

[raymondmetcalf]

Cheers you guys I need to learn more on fuel trims at 70 love it.

[mikeburdi]

Another great video and teaching moment! I totally agree with your call on the MAF. All of your data was pretty much pointing in that direction and then once seeing that it was an aftermarket sensor, I was convinced that was going to be your problem. Great call and you are definitely not a parts changer! Sometimes we have to weigh out the cost of a part versus another hour of diag just to end up back at the same place. Well done Danner duo! 😅

[bmpn]

It'd be nice if we could somehow put together a known good MAF reference table everybody could contribute to. Year, make, model, engine, intake air temp, idle rpm, coolant temp, and mass airflow amount. I think it'd be especially helpful on the smaller engines and forced induction stuff. I know I've seen on some of Bernie's videos where they have a VE database built into their diagnostic system on vehicles they've collected the data on but it'd be nice if we had just a general reference at idle for everybody to look at.

[Pablo_Automotive]

Thank you Paul for another great video where persistence and data clearly showed the fault, I take this opportunity to wish you and your family Merry Christmas wishing you the best

[frankoattes]

5 mins in and I’m thinking it’s maf! I’m thinking this because I already had a similar issue, but it was over fueling. No codes in the system but the maf reading was around 4.9v. Cold, sensor was clean! I took one from another vehicle and it solved the issue. We had this car sitting for a month with one of the techs just throwing parts at it! I had a look at the data and notice the maf reading were not as per the reference values. Sometimes it pays to read your shop manuals when looking for no code faults just to see if anything jumps out at you. I was lucky to find this, I think the other techs frustration made him lose his thought train.

[Drescars]

Rich and lean codes are a pain!! But you always mail them… thank you for another great video, I learned so much just watching your videos!!! Merry Christmas to you and your family and a Happy New Year!!!

[shepherdsfleetservicesllc]

I want say that's great thing you added it with humble mechanic on tool box build. Merry Christmas and God bless. Hopefully next year our company and help with it.

[nelsonnarciso]

Good thing I own a 2008 sx4 all wheel drive . Good to bank this one into my suzuki vault of repair data. Thank you. Merry Christmas to you and your family.

[Portuguese-linguica]

Caleb great job filming and editing. Paul & Dan great job on being cool dudes and the service you provide.

[williamgagnonroadboxservice]

Can’t say enough about the things you SMA And Pine Hollow have given to me this year.
It’s Christmas everyday from you guys. Thank You so much!!
And Stay warm
Merry Christmas to you all and your familys

[onemechca]

Thanks Paul. Merry Christmas to you and family. Merry Christmas to the entire SD community.

[lloydwakefield]

GBY All!🙏❤😊Thank you for bringing uncommon knowledge to the common people❤😊

[paulfiebke]

Loved it. I'm going through the same thing on a Honda. Good seen you and your brother. may God bless you all and your family